That price is backed by a strong four-year, 100,000 kilometre warranty, and the brand also offers capped price servicing for five years or 125,000km, whichever comes first (with an average annual cost of $746). Read full pricing and specifications for the Q50 here.

The engine is a unit shared with the Benz in the C250 specification – a 2.0-litre turbocharged four-cylinder with 155kW of power and 350Nm of torque. However, while Mercedes claims a fuel use figure of just 6.0 litres per 100 kilometres, the Q50’s chubby kerb weight – from 1646 kilograms, compared to the C-Class’ lithe 1465kg mass – means it uses 7.3L/100km.

On paper it isn’t that big of a deal – an extra litre of juice every hundred kilometres likely won’t raise many eyebrows – but it does mean that in higher trim levels this Q50 can’t hit the environmental target of 7.0L/100km to would enable it to forego the luxury car tax. That in turn means higher on-road costs for buyers.

It’s a shame, because the new engine is the most convincing powertrain offering in the Q50 line-up, with smooth response on the open road and linear power delivery under firm acceleration.

While we didn't get a chance to test Infiniti’s acceleration claim of 7.3 seconds from 0-100km/h, the engine felt willing enough despite the heft of the car.

Power goes to the rear wheels via a seven-speed automatic, which shuffles through the cogs smoothly with a penchant for choosing the highest gear possible to keep fuel use low. That can be undone by switching to Sport mode, and the ‘box will hold gears in manual mode.

As good as the engine is, the rest of the Q50’s drive experience suffers the same issues we’ve pointed out in the past when testing different variants of the car.

The ride quality is perhaps the most disappointing element, with a clumsy, fidgety nature that is no doubt exacerbated by the car’s run-flat tyres. Those stiff-walled Bridgestone Potenza treads are otherwise impressive in terms of grip, but there’s a niggling rigidity to the ride that can fluster occupants.

The firm suspension of the Q50 enables it with a degree of cornering prowess, but the weight of the car is noticeable through corners – it never feels as light or agile as some of its rivals, and can be unwieldy if you press on in sharper bends. The front-end does feel notably less weighty with the petrol engine than it does in the diesel, biting down on the road with more conviction.

The steering, too, lacks the innate precision of many of its competitors. We tested the GT model, which has a standard electro-hydraulic power steering unit, and found the setup to be quite chatty to the driver’s hands, offering plenty of feedback and feel through the wheel, but suffering from inconsistent weight and response. There are two modes that can be selected – Standard or Heavy – with the better compromise being the former.

Higher-spec Q50 models – the S and S Premium – are fitted with the brand’s Direct Adaptive Steering system, which uses steer-by-wire technology to control what happens at the front wheels.

Infiniti claims the system has been designed to shield the driver from unwanted feedback through the steering wheel, and it jiggles and wiggles less in the driver’s hands, but it also removes a critical element of control when pushing hard through twisty sections of road. Not everyone will care about that, but for us it is somewhat unnerving.

There are even more modes to be selected than the standard setup: there are three options for the amount of effort required (light, standard, heavy), and three options for the amount of response (casual, standard, quick).

Choose light and casual and the steering feels uninvolving, while with quick and heavy selected it is faster to turn in, but still lacks meaningful feel. For us, standard effort and quick response is the most likable setting, but even then the steering can be inconsistent at different speeds.

Nothing has changed inside the cabin for the Q50, with the cockpit remaining something of a hit or miss affair.

It has comfortable supportive seats up front, which offer decent cushioning for longer trips. All spec levels get electric seat adjustment for those up front, while the driver also gets electric steering wheel reach and rake adjustment.

Rear seat space is good for the most part with decent knee-room, though head-room is not as generous as it could be, particularly for those with longer torsos. The amount of space backseat passengers have to wiggle their toes is impinged upon by how low those up front like their seat base set.

All Q50s have rear air-vents, but while the back pew is well ventilated, it is quite noisy due to tyre roar, and there’s a lack of storage for those being chauffeured as no Q50s have rear door pockets.

For those up front, storage is adequate, and the boot is impressively large (500 litres), offering easily enough space for an oversized golf bag, big baby buggy or a few large suitcases.

When it comes to interior highlights, it’s hard to ignore the fact that many of the buttons and switches you find in a Q50 can also be seen in Nissan products.

However, tech fans will no doubt appreciate Infiniti’s Intouch twin-screen infotainment and control system which can access emails, calendar, and sync popular apps such as Facebook, Google, TripAdvisor and Reuters by linking to Android phones via Bluetooth and iPhones via USB.

The system employs a higher-resolution 8.0-inch touch-sensitive unit below and a more pixelated 7.0-inch display - which showcases the standard sat-nav and reverse-view camera - on top, the latter of which looks less impressive than it otherwise might.

Inconsistency remains the Q50's issue, and while its new engine improves the car’s drivability and its pricing and generous equipment could well be enough to woo coin-conscious buyers, the Q50 remains one of the also-rans in what is arguably the toughest segment of the luxury car market.